A323415 - OEIS

%I #6 Jan 13 2019 19:30:46

%S 1,14,84,120,1180,1450,10180,12784,100180,101180,114500,139204,

%T 1100180,10000180,10010180,10111180,11000180,85937220,101011180,

%U 101101180,101110180,101111180,110000180,111001180,111100180,111101180,111110180

%N Numbers equal to the carryless sum of their divisors.

%C Equivalently, numbers k such that A323394(k) = k.

%H <a href="/index/Ca#CARRYLESS">Index entries for sequences related to carryless arithmetic</a>

%e For k = 14:

%e - the divisors of 14 are: 1, 2, 7, 14,

%e - the sum of the units are: 1 + 2 + 7 + 4 = 14 == 4 (mod 10),

%e - the sum of the tens are: 1,

%e - hence A323394(14) = 14 and 14 belongs to the sequence.

%o (PARI) isok(n, base=10) = my (v=[]); fordiv (n, d, my (w=Vecrev(digits(d, base))); v=vector(max(#v, #w), k, (if (k>#v, w[k], k>#w, v[k], (v[k]+w[k])%base)))); fromdigits(Vecrev(v), base)==n

%Y Cf. A323394.

%K nonn,base

%O 1,2

%A _Rémy Sigrist_, Jan 13 2019